This invention relates to covert receiving systems and more particularly to a receiving system that can be readily worn and concealed in the person of the wearer and that enables the user thereof to receive the message content of incoming inaudible audio signals without the awareness of others.
In the field of law enforcement and other areas, there has been a long standing need for an audio communication system to convertly convey voice bandwidth information signals to an individual. In such applications, for obvious reasons, it is important that the communication system be designed to operate covertly, that is, it is capable of receiving incoming message information without emitting sounds or other signals which could be perceived by others and is concealable from the view of others.
Heretofore, a number of serious attempts have been made to meet the need for covert communication. However, not too successfully. For example, according to a prior art system, a miniature receiver has been provided that is designed for placement within the ear cavity of a user. Thus, it is readily noticeable and not concealed from the views of others. According to the prior art, there s also found a miniature receiver mountable in the mouth of individuals by denuding one or more of the teeth and physically connecting the receiver to the exposed nerves in such a manner that received messages are transmitted via nerve conduction so that the user "hears" the message. It is also found that the receiver must be permanently affixed to the exposed nerves of the teeth by orthodontic surgery and can only be removed by the same. The receiver is also fabricated to receive radio frequency (RF) signals directly which requires greater circuit complexity and may be more unreliable than an inductive coupling audio system. The problems and shortcomings of such a system are obvious. It is highly impractical; it subjects the wearer to great inconvenience to say the least. Furthermore, it exposes the wearer to possible injury to his tissue, nerve and gum structure.
Thus, such a system is highly impractical and costly to wear, even after assuming the aforementioned possible injury to the person can be overlooked. Moreover, such a receiver is not capable of receiving incoming inaudible induction coupled audio signals.
Thus, there are a number of problems and shortcomings associated with the prior art; the prior art device is not capable of receiving inaudible audio bandwidth signals. Also the prior art device is not readily concealable. Accordingly, no prior art device has been able to meet the need of the peculiar demand placed on such a covert receiving system. Yet there is a great need and demand for a receiving system capable of enabling the user covert and concealed hearing without generating audible sound.